{
  "abstract": "Correlated decoding improves matching and clustering surface-code decoders by reweighting one decoding subgraph conditioned on the other's correction. We show that standard reweighting can cause correlated decoders to fail on size-$(d-1)/2$ fault configurations that a distance-$d$ code should correct, reducing error suppression deep below threshold. Under circuit-level noise, a single first-pass edge can discount several correlated edges, even though their joint occurrence requires additional independent faults, so the decoder favors an over-discounted correction. Regularizing the reweighting rule restores the nominal distance scaling and a clear correlated-decoding advantage.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.26785",
  "author_total": 4,
  "authors": [
    {
      "name": "César Hernando de la Fuente"
    },
    {
      "name": "Joonas Majaniemi"
    },
    {
      "name": "Evert van Nieuwenburg"
    },
    {
      "name": "Felix Frohnert"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/33y3gby95amfy.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.26785",
  "fulltext_url": null,
  "id": "33y3gby95amfy",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.26785",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Computing Algorithms and Architecture"
    ]
  ],
  "openalex": "W7223040972",
  "pdf_url": "https://arxiv.org/pdf/2610.26785",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/33y3gby95amfy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2610.26785",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.26785"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Correlated decoding loses the surface code's effective distance below threshold",
  "title_text": "Correlated decoding loses the surface code's effective distance below threshold",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/33y3gby95amfy",
  "venue": "arXiv",
  "versions": []
}